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 ambassadors of India to the United States
Table title:
List of Indian Ambassadors to the United States
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Name </th><th colspan=1 rowspan=1 > Photo </th><th colspan=1 rowspan=1 > Entered office </th><th colspan=1 rowspan=1 > Left office </th><th colspan=1 rowspan=1 > Notes </th></tr>
<tr> <td colspan=1 rowspan=1 > Asaf Ali </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 1947 </td><td colspan=1 rowspan=1 > 1948 </td><td colspan=1 rowspan=1 > Lawyer and former Governor of Odisha. </td></tr>
<tr> <td colspan=1 rowspan=1 > Benegal Rama Rau </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 1948 </td><td colspan=1 rowspan=1 > 1949 </td><td colspan=1 rowspan=1 > 4th Governor of Reserve Bank of India. </td></tr>
<tr> <td colspan=1 rowspan=1 > Vijaya Lakshmi Pandit </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 1949 </td><td colspan=1 rowspan=1 > 1951 </td><td colspan=1 rowspan=1 > First Woman President of the United Nations General Assembly (1953) </td></tr>
<tr> <td colspan=1 rowspan=1 > Binay Ranjan Sen </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1951 </td><td colspan=1 rowspan=1 > 1952 </td><td colspan=1 rowspan=1 > Director General of Food and Agriculture Organization (1956–67) </td></tr>
<tr> <td colspan=1 rowspan=1 > Gaganvihari Lallubhai Mehta </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1952 </td><td colspan=1 rowspan=1 > 1958 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > M. C. Chagla </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1958 </td><td colspan=1 rowspan=1 > 1961 </td><td colspan=1 rowspan=1 > Eminent lawyer </td></tr>
<tr> <td colspan=1 rowspan=1 > Braj Kumar Nehru </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1961 </td><td colspan=1 rowspan=1 > 1968 </td><td colspan=1 rowspan=1 > ICS officer, Governor of seven different states. Also served as Economic Affairs Secretary. </td></tr>
<tr> <td colspan=1 rowspan=1 > Ali Yavar Jung </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1968 </td><td colspan=1 rowspan=1 > 1970 </td><td colspan=1 rowspan=1 > Governor of Maharashtra, VC of AMU, VC of Osmania univ. </td></tr>
<tr> <td colspan=1 rowspan=1 > Lakshmi Kant Jha </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1970 </td><td colspan=1 rowspan=1 > 1973 </td><td colspan=1 rowspan=1 > ICS, Secy Industries, Commerce, Finance, Secy to the PM,8th Governor of Reserve Bank of India,Governor of J&K </td></tr>
<tr> <td colspan=1 rowspan=1 > T. N. Kaul </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1973 </td><td colspan=1 rowspan=1 > 1976 </td><td colspan=1 rowspan=1 > ICS, former Foreign Secretary. </td></tr>
<tr> <td colspan=1 rowspan=1 > Kewal Singh </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1976 </td><td colspan=1 rowspan=1 > 1977 </td><td colspan=1 rowspan=1 > ICS, former Foreign Secretary. </td></tr>
<tr> <td colspan=1 rowspan=1 > Nanabhoy Palkhivala </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1977 </td><td colspan=1 rowspan=1 > 1979 </td><td colspan=1 rowspan=1 > Eminent lawyer </td></tr>
<tr> <td colspan=1 rowspan=1 > K. R. Narayanan </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 1980 </td><td colspan=1 rowspan=1 > 1984 </td><td colspan=1 rowspan=1 > 10th President of India </td></tr>
<tr> <td colspan=1 rowspan=1 > K. Shankar Bajpai </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1984 </td><td colspan=1 rowspan=1 > 1986 </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > P. K. Kaul </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1986 </td><td colspan=1 rowspan=1 > 1989 </td><td colspan=1 rowspan=1 > IAS officer, former Cabinet Secretary of India. Also served as Finance Secretary, Defence Secretary and Commerce Secretary. </td></tr>
<tr> <td colspan=1 rowspan=1 > Karan Singh </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 1989 </td><td colspan=1 rowspan=1 > 1990 </td><td colspan=1 rowspan=1 > Titular Maharajah of Jammu and Kashmir </td></tr>
<tr> <td colspan=1 rowspan=1 > Abid Hussain </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 1990 </td><td colspan=1 rowspan=1 > 1992 </td><td colspan=1 rowspan=1 > IAS officer, former Commerce Secretary. </td></tr>
<tr> <td colspan=1 rowspan=1 > Siddhartha Shankar Ray </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 1992 </td><td colspan=1 rowspan=1 > 1996 </td><td colspan=1 rowspan=1 > Minister of Education, Chief Minister of West Bengal </td></tr>
<tr> <td colspan=1 rowspan=1 > Naresh Chandra </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 1996 </td><td colspan=1 rowspan=1 > 2001 </td><td colspan=1 rowspan=1 > IAS officer, former Cabinet Secretary of India. Also served as Home Secretary, Defence Secretary and Finance Secretary. </td></tr>
<tr> <td colspan=1 rowspan=1 > Lalit Mansingh </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 2001 </td><td colspan=1 rowspan=1 > 2004 </td><td colspan=1 rowspan=1 > IFS officer, former Foreign Secretary and Indian High Commissioner to the United Kingdom. </td></tr>
<tr> <td colspan=1 rowspan=1 > Ronen Sen </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 2004 </td><td colspan=1 rowspan=1 > 2009 </td><td colspan=1 rowspan=1 > IFS officer. </td></tr>
<tr> <td colspan=1 rowspan=1 > Meera Shankar </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 2009 </td><td colspan=1 rowspan=1 > 2011 </td><td colspan=1 rowspan=1 > IFS officer. </td></tr>
<tr> <td colspan=1 rowspan=1 > Nirupama Rao </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 2011 </td><td colspan=1 rowspan=1 > 2013 </td><td colspan=1 rowspan=1 > IFS officer, former Foreign Secretary. </td></tr>
<tr> <td colspan=1 rowspan=1 > Subrahmanyam Jaishankar </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 2013 </td><td colspan=1 rowspan=1 > 28 January 2015 </td><td colspan=1 rowspan=1 > IFS officer, former Foreign Secretary. </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Arun Kumar Singh </td><td colspan=1 rowspan=1 > - </td><td class="highlighted"  colspan=1 rowspan=1 > 2015 </td><td class="highlighted"  colspan=1 rowspan=1 > 2016 </td><td colspan=1 rowspan=1 > IFS officer. </td></tr>
<tr> <td colspan=1 rowspan=1 > Navtej Sarna </td><td colspan=1 rowspan=1 > - </td><td colspan=1 rowspan=1 > 2016 </td><td colspan=1 rowspan=1 > 20 December 2018 </td><td colspan=1 rowspan=1 > IFS officer </td></tr>
<tr> <td colspan=1 rowspan=1 > Harsh Vardhan Shringla </td><td colspan=1 rowspan=1 >  </td><td colspan=1 rowspan=1 > 11 January 2019 </td><td colspan=1 rowspan=1 > Incumbent </td><td colspan=1 rowspan=1 > IFS officer </td></tr>
</table>
Question:
Who is Arun Kumar Singh?
Answer:
Arun Kumar Singh was the Indian Ambassador to the United States from 2015 to 2016.