Apiece of land that juts out into the sea
a. sea stack
b. sandbar
c. spit
d. headland

Letter D

Explanation:

In geography, a peninsula is a piece of land almost entirely surrounded by water that has a connection to the mainland or other larger portion of land by means of an isthmus (narrow strip of land that connects, over the waters of an ocean or sea, between two portions of large-scale emerged land). Interestingly a Headland, which is the right answer to the question, is considered a small peninsula.

the correct answer would be 6 feet.