Hoping to rebound from their road loss to the Vikings, the Texans went home for a Week 10 duel with the Baltimore Ravens.  Both teams were supposed to play each other in Week 2, but Hurricane Ike forced them to reschedule their game to this week. With QB Matt Schaub out with an injury, back-up QB Sage Rosenfels was given the start. In the first quarter, Houston trailed early as Ravens QB Joe Flacco completed a 43-yard TD pass to WR Yamon Figurs.  In the second quarter, the Texans responded with kicker Kris Brown getting a 23-yard field goal.  Baltimore would answer on a Houston blunder, as rookie OT Duane Brown committed a holding penalty in his own endzone, giving the Ravens a safety.  Baltimore added onto their lead as kicker Steven Hauschka got a 54-yard field goal.  The Texans closed out the half with Brown nailing a 48-yard field goal. In the third quarter, the Ravens increased their lead as RB Willis McGahee got a 1-yard TD run.  Houston responded as Rosenfels completed a 60-yard TD pass to WR Kevin Walter.  However, in the fourth quarter, Baltimore greatly pulled away as Flacco completed a 1-yard TD pass to TE Todd Heap (with a 2-point conversion pass to WR Derrick Mason), QB Troy Smith completed a 14-yard TD pass to Heap, and McGahee getting a 4-yard TD run.
Question: How many touchdowns did the Ravens score in the fourth quarter?
Answer: 3