Answer: <u>Guanine
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According to Chargaff's rule, the base pairing in the DNA and RNA is fixed. Adenine always pairs with Thymine in DNA and Uracil in RNA. Guanine pairs up with cytosine. This complementary base pairing is universal and constant. That's why amounts are also equal. It means if cytosine is 20% in any DNA sample, then amount of guanine would be 20% as well.
Battery acid is acidic in nature so its pH will be more.if we add a base its acidity level decreases and it becomes a poor acid. here water acts as a base to decrease the pH value and acidic nature of a acid substance that is battery acid.
I believe the answer is b.
The Gram-positive bacteria have a thicker cell wall than the Gram-negative bacteria.