There is a typographical error in the list of choices, such that the correct answer is not among them.
Weight = (mass) x (gravity)
Gravity on Earth = 9.8 m/s²
Weight of ONE average person = (65 kg) x (9.8 m/s²) = 637 N.
Weight of all the people on Earth = (6.5 billion) x (637 N)
Weight of all = (6.5 x 10⁹) x (637 N)
Weight of all = 4,140.5 x 10⁹ N
Weight of all = 4.1405 x 10¹² N
"one trillion" means 10¹²
Weight of all = 4.1405 Trillion N .
Choice-A has the correct digits, but the decimal point is in the wrong place. "41.4 trillion" is 10 times too big.
There was a typographical error, either when the book or homework sheet was getting ready to be printed, or else when Brennarfa copied the question into Brainly.
If Jolly Old Hellhound showed us how he worked the problem, this strange glitch would jump right out for everyone to see.
So here's how it stands:
-- When they made up the test, they put the correct answer in 'A', and they put 'A' on the teacher's answer-key.
-- When the test got printed, 'A' got printed wrong.
-- Hellhound said 'A'. That agreed with the answer-key, but we have no idea how he chose 'A' for the answer.
-- Brenna wrote Hellhound's choice on the test. It agreed with the answer-key, and was marked correct.
-- Hellhound should have gotten the credit for that answer, but Brenna pretended like it was hers.
-- Brenna still doesn't know how to solve the problem, but loved the 100% on the test and doesn't care.
-- We all live happily ever after.
