As Long as Indifference Curves Are Convex to the Origin

As long as indifference curves are convex to the origin, utility maximisation will take place

A) where the budget constraint intersects the indifference curve.
B) where the consumer spends all of his income on one good.
C) where the consumer spends half of his income on each good.
D) at the point at which the indifference curve is just tangent to the budget constraint.