A Blimp Has a Velocity Of $8.2 \mathrm{~m} / \mathrm{s}$ Due West Relative to the Air

Multiple Choice

A blimp has a velocity of $8.2 \mathrm{~m} / \mathrm{s}$ due west relative to the air. There is a wind blowing at $3.5 \mathrm{~m} / \mathrm{s}$ due north. The speed of the balloon relative to the ground is

A) $11.7 \mathrm{~m} / \mathrm{s}$
B) $8.9 \mathrm{~m} / \mathrm{s}$
C) $7.4 \mathrm{~m} / \mathrm{s}$
D) $4.7 \mathrm{~m} / \mathrm{s}$
E) Some other speed (specify)