Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
List of Minder episodes
Table title:
Series 1
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Episode </th><th colspan=1 rowspan=1 > Title </th><th colspan=1 rowspan=1 > First aired </th></tr>
<tr> <td colspan=1 rowspan=1 > 1 </td><td colspan=1 rowspan=1 > "Gunfight at the OK Laundrette" </td><td colspan=1 rowspan=1 > 29 October 1979 </td></tr>
<tr> <td colspan=3 rowspan=1 > Terry is caught up in an armed robbery at a laundrette owned by gangster-turned-successful businessman Alfie Cavallo. The robbery goes wrong and all present are held at gunpoint. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Dave King as Alfie Cavallo, Hilary Mason as Mrs. Mayhew, Donald Burton as Chief Superintendent, Arnold Diamond as Bernie. </td></tr>
<tr> <td colspan=1 rowspan=1 > 2 </td><td colspan=1 rowspan=1 > "Bury My Half at Waltham Green" </td><td colspan=1 rowspan=1 > 5 November 1979 </td></tr>
<tr> <td colspan=3 rowspan=1 > Terry guards Albert Stubbs, a newly released bank robber until he can retrieve the stolen money he has buried. He discovers that he's actually lumbered with George Wilson, a look-alike decoy, to divert attention from the 'real' Stubbs, who is being housed at Arthur's flat. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Ann Lynn as Rose Mellors, Kenneth Cope as Stubbs, Nicky Henson as George, Tony Selby as Jacko. </td></tr>
<tr> <td colspan=1 rowspan=1 > 3 </td><td colspan=1 rowspan=1 > "The Smaller They Are" </td><td colspan=1 rowspan=1 > 12 November 1979 </td></tr>
<tr> <td colspan=3 rowspan=1 > Scotch Harry, a sneak thief, grabs a suitcase full of cash, but it proves to be counterfeit and he's out of his depth, tangling with international currency smugglers who don’t baulk at violence. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Phil McCall as Scotch Harry, David Jackson as Big Stan, George Tovey as Pub Landlord, Hilary Ryan as Airline Receptionist. </td></tr>
<tr> <td colspan=1 rowspan=1 > 4 </td><td colspan=1 rowspan=1 > "A Tethered Goat" </td><td colspan=1 rowspan=1 > 19 November 1979 </td></tr>
<tr> <td colspan=3 rowspan=1 > Terry guards a visiting Lebanese businessman/politician at a West Kensington flat. Initially told it's a simple job, he finds that the visitor has been set up for a politically motivated assassination. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Lee Montague as Bassam Sayin, Kenneth Griffith as Dai Llewellyn, Michael Sheard as Elliot, Nadim Sawalha as Sardi, Patrick Jordan as Police Inspector, Ian Collier as 1st Police Sergeant, David Millett as 2nd Police Sergeant. </td></tr>
<tr> <td colspan=1 rowspan=1 > 5 </td><td colspan=1 rowspan=1 > "The Bounty Hunter" </td><td colspan=1 rowspan=1 > 26 November 1979 </td></tr>
<tr> <td colspan=3 rowspan=1 > Terry and Arthur help a young widow who's been swindled out of her life savings in a Majorcan property scheme run by Freddie Fenton, a crooked businessman. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Derek Jacobi as Freddie Fenton, June Ritchie as Jo Williams, George Layton as Des, James Aubrey as Graham Hurst, Tony Steedman as Ralph Hurst, Christopher Biggins as Harold, Keith Alexander as Andy. </td></tr>
<tr> <td colspan=1 rowspan=1 > 6 </td><td colspan=1 rowspan=1 > "Aces High – and Sometimes Very Low" </td><td colspan=1 rowspan=1 > 3 December 1979 </td></tr>
<tr> <td colspan=3 rowspan=1 > After being banned by several casinos for being too successful, Maurice Michaelson, a professional gambler, participates in an illegal high-stakes card game, with Terry minding him. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Anthony Valentine as Maurice, Marina Sirtis as Stella, Kevork Malikyan as Chris, David Baron as Casino Manager. </td></tr>
<tr> <td colspan=1 rowspan=1 > 7 </td><td colspan=1 rowspan=1 > "The Bengal Tiger" </td><td colspan=1 rowspan=1 > 10 December 1979 </td></tr>
<tr> <td colspan=3 rowspan=1 > Terry and Arthur are drawn into the problems of newspaper shop owner Mr. Mukerjee, whose daughter Indira has been promised in arranged marriages to several older wealthy Indian businessmen in return for dowry payments. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Saeed Jaffrey as Mukerjee, Graham Stark as Car owner, Ahmed Khalil as Aslam, Roy Evans as Elderly Man, Eamonn Boyce as Barman, Clive Hornby as Norman Gibbons, Mike Grady as Kev, Shireen Anwar as Indira. </td></tr>
<tr> <td colspan=1 rowspan=1 > 8 </td><td colspan=1 rowspan=1 > "Come in T64, Your Time is Ticking Away" </td><td colspan=1 rowspan=1 > 17 December 1979 </td></tr>
<tr> <td colspan=3 rowspan=1 > Terry is persuaded to go undercover as a driver (in a clapped-out Austin A60 Cambridge) to find out who's sabotaging the minicab firm Arthur co-owns. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Alfred Burke as Kevin, Daphne Anderson as Katie, George Layton as Des, Oscar James as Dave, W. Morgan Sheppard as John, Eric Mason as Paddy. </td></tr>
<tr> <td colspan=1 rowspan=1 > 9 </td><td colspan=1 rowspan=1 > "Monday Night Fever" </td><td colspan=1 rowspan=1 > 7 January 1980 </td></tr>
<tr> <td colspan=3 rowspan=1 > Arthur falls heavily for Sharon, a glamorous would-be nightclub singer and offers to manage her career, despite her terrible voice. Chris, the club owner, who's been paid by Arthur to help launch her career with massive publicity, fails to come good. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: Sheila White as Sharon Nightingale, Peter Blake as Barry, Eric Deacon as Chris Lambert, Brian Croucher as Big John, Anthony Heaton as Vic Piner, Tommy Wright as Henry Piner, Michael Melia as Freddie. </td></tr>
<tr> <td colspan=1 rowspan=1 > 10 </td><td class="highlighted"  colspan=1 rowspan=1 > "The Dessert Song" </td><td class="highlighted"  colspan=1 rowspan=1 > 14 January 1980 </td></tr>
<tr> <td colspan=3 rowspan=1 > Terry and Arthur assist Charlie, a Greek Cypriot newly arrived in London, but learn that he's come with a rifle in order to kill Omar, the Turkish Cypriot man he believes killed his brother in Cyprus. </td></tr>
<tr> <td class="highlighted"  colspan=3 rowspan=1 > Guest stars: Peter Bland as Charlie, Diane Keen as Christina Kostos, Daniel Hill as Johnny, Godfrey James as Omar, Michael Angelis as Nick. </td></tr>
<tr> <td colspan=1 rowspan=1 > 11 </td><td colspan=1 rowspan=1 > "You Gotta Have Friends" </td><td colspan=1 rowspan=1 > 21 January 1980 </td></tr>
<tr> <td colspan=3 rowspan=1 > 'Pretty Billy' Gilpin turns up at Arthur's home, badly injured, and begging for assistance. Terry drives him to where he wants to go, but Billy is later found drowned. </td></tr>
<tr> <td colspan=3 rowspan=1 > Guest stars: George Baker as Altman, Roy Kinnear as 'Big Kev' Whaley, David Buck as Billy, Deborah Grant as Lady Ingrave, Brian Hall as Alan, Allan Surtees as D.I. </td></tr>
</table>
Question:
What episode of Minder did Diane Keen appear in, and whom did she play?
Answer:
In 1980, Diane Keen appeared as Christina in the Series 1 episode of Minder titled "The Dessert Song".