The grammatically correct and meaningful sentence is:
“Nowadays singing is a very profitable profession.”
Let’s analyze:
- (A) ✅ Correct — natural structure, no article before “singing,” and uses “a very profitable profession.”
- (B) ❌ “the singing” sounds awkward and unnecessary here.
- (C) ❌ Missing article “a” before “very profitable profession.”
- (D) ❌ “Profession” capitalized incorrectly; also awkward use of “the.”