If Y Varies Directly as X, Find a Linear Function $y = 0.6$

Multiple Choice

If y varies directly as x, find a linear function which relates them.
- $y = 0.6$ when $x = 1.2$

A) $f ( x ) = 0.6 x$
B) $f ( x ) = 0.5 x$
C) $f ( x ) = x - 0.6$
D) $f ( x ) = 2 x$