The Point of Tangency Between an Isocost Line and an Isoquant

The point of tangency between an isocost line and an isoquant is necessarily

A) the profit-maximizing combination of inputs that should be hired to produce that output level.
B) the least costly combination of inputs that can be hired to produce the output level.
C) both the profit-maximizing and least costly combination of inputs that can be used to produce the output level.
D) the minimum amount of output that can be attained for that level of expenditure.