(A) With that, he turns [A] / turned [B] on his heal [A] / heel [B] and fled.
(B) The singer assented [A] / ascented [B] to the request for an encore.
(C) It is, sometimes useful, to plumb [A] / plum [B] someone’s thoughts.
(D) The school had a great interest in music and was forming a choral [A] / coral [B] society.
Option: (b)
BBAAA: The 1st sentence is in the past tense as indicated by ‘fled’ so option ‘B’ is correct, heel means the part of the foot and heal is to cure. Assented means to agree and ascent an upward movement. Therefore, the singer agreed to the request for an encore. Plum is a fruit and plumb means to examine closely or deeply. Therefore, it is useful to examine one’s thoughts. Choral means of a choir and coral is the hard, variously colored, calcareous skeleton secreted by certain marine polyps as in, something made of coral.