Howard describes a model system used to test the molecular weight distribution of acondensation polymer (g. j. howard, j. polym. sci. 37, 310 (1959)): "the polymer sample was an acetic acid-stabilized equilibrium nylon-6,6. analysis showed it to have the following end group composition (in equivalents per 106 g): acetyl = 28.9, amine = 35.3 and carboxyl = 96.5. the number average degree of polymerization is, therefore, 110 and the conversion degree (= extent of reaction) = 0.9909.for nylon-6,6, 99% of the carboxylic acid groups are know to have reacted.
calculate the average of mn, mw and mz.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.