Starting lineups: HOUSTON - DEFENSE: DE Antonio Smith, DT Shaun Cody, DT Amobi Okoye, DE Mario Williams, LB Brian Cushing, LB Kevin Bentley, LB Darryl Sharpton, CB Glover Quinn, CB Kareem Jackson, SS Bernard Pollard, FS Eugene Wilson. Coming off their bye week the Texans played at Lucas Oil Stadium for an AFC South division rivalry match against the Indianapolis Colts. In the first quarter the Texans trailed early as QB Peyton Manning completed a 2-yard TD pass to TE Jacob Tamme. The Texans struggled further in the 2nd quarter when Matt Schaub's pass was intercepted by CB Kelvin Hayden and returned 25 yards for a touchdown. They soon responded with kicker Neil Rackers nailing a 53-yard field goal. The Texans fell further behind with kicker Adam Vinatieri getting a 48-yard field goal. This was followed in the third quarter by Manning throwing a 15-yard TD pass to WR Reggie Wayne. The Texans' offense broke through with Schaub connecting to WR Andre Johnson on a 28-yard TD pass. The Colts replied with Vinatieri hitting a 23-yard field goal. The Texans tried to fight back but only came away with a touchdown after RB Arian Foster got a 6-yard TD run. The Colts closed the game with Vinatieri making a 36-yard field goal.
Question: who is the texans' runningback?
Answer: Arian Foster