(A) Esters have lower boiling points than isomeric carboxylic acids. 
(R) Carboxylic acids have strong inter molecular hydrogen bonding whereas esters do not form hydrogen bonding

(A) is true but (R) is false

Both (A) and (R) are true but (R) is not the correct explanation of (A)

Both (A) and (R) are true and (R) is the correct explanation of (A)

Both (A) and (R) are false