I need helppp plzzz When throwing a ball, why does the triceps muscle contract?

•The contraction of the triceps muscle causes the arm to flex

•The contraction of the triceps muscle causes the arm to extend

•When added to the force of the biceps contracting it provides extra force to the ball.

•The triceps muscle needs to contract in order to keep the biceps muscle from relaxing ,

You can look it up online and some images should pop up 

Reaction involved in present system is :   c12h22o11 + h2o → 2 c6h12o6the reaction system is obeying following rate law:   rate = k[c12h22o11]thus, it is a first order reaction.now, for 1st order reactionrate constant (k) =  given: initial conc. = 3.0 g, final conc. = 2.7 g, t = 2.5 h∴rate constant (k) =  ∴ k = 0.04215 h-1now, for 1st order reaction, half life = 0.693/k = 0.693/0.04215 = 16.4 hthus correct answer is option b