Some bases are attached to sugars whereas other bases are attached to phosphates.
a. true
b. false

The correct answer will be option-false.

Explanation:

DNA is made up of repeating monomer units called nucleotides which form both the strand of the DNA.  Each nucleotide is composed of a five-carbon sugar called deoxyribose, a phosphate group and four different types of nitrogenous bases.

The nitrogenous bases are of two types: purines with four nitrogen like adenine and guanine and pyrimidines with two nitrogen like thymine and cytosine.

According to the Chargaff rule, purine binds pyrimidine always in the DNA where adenine binds thymine and cytosine binds guanine.

Thus, false is the correct answer.

its temperature is increasing. this causes molecular vibrations to increase.