The idiom "wrap your head around something" means to fully comprehend or understand a complex idea, concept, or situation, especially one that is challenging or difficult to grasp initially. It implies a significant mental effort to process and internalize information, moving from confusion to clarity. When you say you need to "wrap your head around" a new theory or a complicated problem, you are expressing the need to dedicate mental energy to make sense of it and integrate it into your understanding. This phrase is commonly used to describe the cognitive process of overcoming intellectual hurdles.
Option A: Understand something perfectly captures this meaning. The other options are incorrect because they do not relate to the idiom's true sense. "Cover your head" refers to a literal physical action, "avoid learning" is the opposite of understanding, and "read quickly" suggests a superficial engagement rather than deep comprehension. Therefore, the idiom emphasizes the active and often challenging process of achieving complete mental grasp over a subject, making option A the only accurate interpretation.