Two cows, with approximately 1.8 m between their front and hind legs, are standing under a tree

Question:

Two cows, with approximately 1.8 m between their front and hind legs, are standing under a tree during a thunderstorm.
(a) If the equipotential surfaces about the tree just after a lightning strike are as shown, what is the average electric field between Cow A's front and hind legs?
(b) Which cow is more likely to be killed? Explain.