Use the diagram of the right triangle above

For this case what you have to take into account is the following trigonometric relationship:
 TanB = b / a
 We clear the value of b:
 b = a * TanB
 Substituting the values we have:
 b = 10 * Tan (60)
 b = 17.32 m
 
 b = 17.32 m
 option a.

the formula of a slope:

we have the points (-2, 7) and (2, 3). substitute:

answer: the slope is equal -1.