Concept:
Cuneiform is one of the earliest known writing systems.
It was used in ancient Mesopotamia and was written using wedge-shaped marks on clay tablets.
Step 1: Understand cuneiform script.
Cuneiform script was used by ancient civilizations such as the Sumerians, Akkadians, Babylonians, and Assyrians.
It was written mainly on clay tablets.
Step 2: Identify the decipherer.
Henry Rawlinson played a major role in deciphering cuneiform script.
His work on the Behistun inscription helped scholars understand cuneiform writing.
Step 3: Compare with other options.
James Prinsep is associated with deciphering Brahmi script.
John Marshall is associated with archaeology and Indus Valley Civilization.
Henry Rawlinson is associated with cuneiform script.
Step 4: Final conclusion.
Hence, the correct answer is:
\[
\boxed{\text{Henry Rawlinson}}
\]