Researchers hope to gain insight into microscopic life on the Moon. If the lunar probe lands safely on the planet's surface.

Question

How should the two clauses be combined into one sentence?
A.
Researchers hope to gain insight into microscopic life on the Moon, and if the lunar probe lands safely on the planet's surface.
B.
Researchers hope to gain insight into microscopic life on the Moon, if the lunar probe lands safely on the planet's surface.
C.
Researchers hope to gain insight into microscopic life on the Moon; if the lunar probe lands safely on the planet's surface.
D.
Researchers hope to gain insight into microscopic life on the Moon if the lunar probe lands safely on the planet's surface.

Answer 1

D. Researchers hope to gain insight into microscopic life on the Moon if the lunar probe lands safely on the planet's surface.