Answer:
D. f(x) = {0.1x, x≥0; -0.1x, x<0}
Explanation:
The absolute value function has positive slope for x>0. Only two answer choices match that, having an x-coefficient of +0.1.
The function is defined for x=0. Of the two choices C and D, only answer choice D is defined at x=0.
The appropriate choice is D.