Solution:
The correct answer is C.
It's mnemonic device.
Acrostic is a poem (or other form of writing) in which the first letter (or syllable, or word) of each line (or paragraph, or other recurring feature in the text) spells out a word, message or the alphabet The word comes from the French acrostiche from post-classical Latin acrostichis, from Koine Greek from Ancient Greek the "highest, topmost" is a form of constrained writing, an acrostic can be used as a mnemonic device to aid memory retrieval. crostics are common in medieval literature, where they usually serve to highlight the name of the poet or his patron, or to make a prayer to a saint. They are most frequent in verse works but can also appear in prose. The Middle High German poet Rudolf von Ems for example opens all his great works with an acrostic of his name, and his world chronicle marks the beginning of each age with an acrostic of the key figure (Moses, David, etc.).