Given that -1 ≤ v ≤ 1, -2 ≤ u ≤ -0.5, and -2 ≤ z ≤ -0.5 and w = vz/u, then which of the following is necessarily true ?  Choices:
A) -0.5 ≤ w ≤ -2	B) -4 ≤ w ≤ 4	C) -4 ≤ w ≤ 2	D) -2 ≤ w ≤ -0.5	E) None of these
Explanation :   u is always negative. Hence, for us to have a minimum value of vz/u , vz should be positive.   Also for the least value, the numerator has to be the maximum positive value and the denominator has to be the smallest negative value. In other words, vz has to be 2 and u has to be –0.5.   Hence the minimum value of vz/u = 2−0.5 = –4.   For us to get the maximum value, vz has to be the smallest negative value and u has to be the highest negative value.   Thus, vz has to be –2 and u has to be –0.5. Hence the maximum value of vz/u = 2 / -0.5 = 4.   Answer : -4 ≤ w ≤ 4
<result>B</result>
Given that -1 ≤ v ≤ 1, -2 ≤ u ≤ -0.5, and -2 ≤ z ≤ -0.5 and w = vz/u, then which of the following is necessarily true ?