The first Mosque constructed by Prophet Muhammad (PBUH) was

(A) Masjid-ul-Haram
(B) Masjid-e-Nabavi
(C) Masjid-e-Aqsa
(D) Quba Masjid

The answer is: (D) Quba Masjid
The first Masjid (Mosque) constructed by Prophet Muhammad (PBUH) was Quba Masjid. It is located in Madinah, Saudi Arabia.