Prompt

Which of the following operations requires an `unsafe` block in standard Rust? A) Reading a private field of a struct defined in an external crate B) Dereferencing a raw pointer (*const T or *mut T) C) Casting an integer to a float using the `as` keyword D) Calling a generic function with unbounded type parameters Reply with the letter of the correct option (A, B, C, or D).

Expected output

B