What constructs break or bend the normal Syntax patterns of scheme?

let and begin break or bend the normal syntax patterns of the scheme. Explanation:

let performed sequentially from left to right and region of binding indicated by variable. The second binding is done in which the first binding is visible and so on. The syntax is can contain multiple statements by the Begin and END keywords. Begin constructs can be nested and each block can define the variables.

the answer is d underlined.