Answer:
option 4
Step-by-step explanation:
Take any point on the graph different from (0, 0). For example, (2, 10) and se which function verifies:
y = 10x ----> 10 = 10*2 = 20 so NOT
y = 1/5x ----> 10 = (1/5)*2 = 2/5 so NOT
y = 2x ----> 10 = 2*2 = 4 ----> so NOT
y = 5x ----> 10 = 2*5 = 10 -----> YES!!
So, f(x) = 5x verifies and matches the graph
