Çözüldü Subject and Verb Agreement - Time Consistency

As the American population grows, ages, and gains better access to affordable health insurance, the demand for primary medical services ______ expected to skyrocket.

A) are
B) is
C) has been
D) would be
E) was

Correct Choice: B (is)

Official Explanation:
"The subject of this verb is demand, which is singular. Therefore, are must be changed to is."

Note:
"has been", despite being singular, is wrong because it refers to the time from the past to present.
"was" is also wrong because the entry clause is in present tense, so the "demand" cannot be in the past.

McGraw-Hill Education SAT, 2020 Edition
Page 36 (63 in the pdf file), Question 1
Answer and Explanation: page 75 (102 in the pdf file)