Sorry for my tardiness in posting the answer!
The correct answer is : B. 1976-1977
Season opened with: Guys & Dolls (all-black revival)
Followed by:
Going Up (original opening 12/25/1917)
Porgy and Bess (original opening 10/10/1935)
Fiddler on the Roof (9/22/1964)
A Party with Betty Comden and Adold Green (12/23/195

Side by Side by Sondheim (a musical anthology, 4/15/1977)
The King and I, (original opening 3/29/1951)
Season last official opening show was:
Happy End(originally written in Berlin in 1929, Broadway production opened 5/7/1977, starring Meryl Streep and Bob Gunton)
Whew!
Oh yes...there were some new musicals too:
The Robber Bridegroom (starring Barry Bostwick & Patti LuPone)
Music Is
Your Arms Are Too Short To Box with God
Ipi-Tombi
I Love My Wife
Annie
(Beatlemania, but it never officially opened)
Yours for a better Broadway!