The Olmec people ...

constructed giant stone monuments.

built pyramids out of blocks of stone.

developed a writing system with pictographs.

created a system of numbers that included zero.

Constructed giant stone monuments.

The correct answer for above statement is:

A) constructed giant stone monuments.

Explanation:

The Olmec were the first important civilization in Mexico. They existed in the tropical marshes on the Gulf of Mexico in the present-day Mexican states of Veracruz and Tabasco. The name Olmec is a Nahuatl the Aztec language word, it means the rubber people. The Olmec people created giant stone monuments. developed a writing.