Is it true that the precambrian is the largest eon?

yes

Explanation:

"The Precambrian is the largest span of time in Earth's history before the current Phanerozoic Eon (the largest division of geologic time, comprising two or more eras) and is a supereon divided into several eons of the geologic time scale."

Yes, the Precambrian is the largest geological time because it contains 3 eons: Hadean (4,600 - 4,000 MYA), Archean (4,000 - 2,500 MYA) and the Proterozoic (2,500 - 541 MYA). The 3 eons contain eras and many geological periods.

MYA is short for million years ago.

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.

not to sure thinking it would be a hope this