Hoping to rebound from their loss to the Steelers, the Ravens flew to Reliant Stadium for a Week 14 Monday night duel with the Houston Texans.  Baltimore delivered the game's opening strike with a 1-yard touchdown run from running back Willis McGahee.  The Ravens added onto their lead in the second quarter as quarterback Joe Flacco found wide receiver Derrick Mason on a 9-yard and a 26-yard touchdown pass.  The Texans answered with quarterback Matt Schaub completing a 46-yard touchdown pass to wide receiver Andre Johnson. Baltimore struck back to open the third quarter with rookie wide receiver David Reed returning the second half's opening kickoff 103&#160;yards for a touchdown.  Houston responded with kicker Neil Rackers making a 24-yard and a 42-yard field goal.  The Texans tied the game in the fourth quarter as Schaub completed a 7-yard touchdown pass to wide receiver Jacoby Jones, a 5-yard touchdown pass to Johnson, and a successful two-point conversion pass to Jones.  In overtime, the Ravens got the win as cornerback Josh Wilson returned a 12-yard interception for a touchdown.
Question: How many defensive touchdowns were scored?
Answer: 1