The ticked option is the given answer.Shouldn’t the ethynyl group at 6 be considered part of the chain, because even if the other chain is longer, the chain including this ethynyl group contains one more functional group than the other? (Triple bond).

In the above question between carboxylic acid and triple bond,carboxylic acid is the prime functional group and the triple bond is taken as the side chain.So in naming the compound,longest chain including the carboxylic acid is selected.Minimum number is given to it and then numbering is done for the triple bond.As per rule of IUPAC we have to select the longest chain which is the chain containing the COOH as functional group(8-carbons in the chain) and if the chain is selected in a way which includes the ethynyl group at 6 then such chain will be smaller(6-carbons) containing chain.So this ethynyl is not included in the chain.Also the sum of locants will be more in such naming.

Approved