What Coefficient Is Needed in Front of the O₂ Molecule $\mathrm { C } _ { 4 }$

What coefficient is needed in front of the O₂ molecule to balance the following equation? 2 $\mathrm { C } _ { 4 }$ $\mathrm { H } _ { 10 }$ (g) + ________ $\mathrm { O } _ { 2 }$ (g) ? 8 $\mathrm { CO } _ { 2 }$ (g) + 10 $\mathrm { H } _ { 2 }$ O (l)

A) 8
B) 13
C) 5
D) 1