I think <span>A) cattle is the answer
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Answer:
Mental processes
Explanation:
<u>Mental processes </u>are the thoughts, feelings, and motives that each of us experiences privately but that cannot be observed directly.
The people of the Indus Valley civilization had a writing system that no one has been able to decipher, though many have tried. It's one of the reasons that it is one of the least known about ancient civilizations. So I would say that the indecipherable writing system is the greatest mystery.
The answer to your question is D
