Hi .
The answer is A) Species.
Reason : Simple basic concept.
Genus is a group of species which are similar to each other.
For Example : I take Genera Solanum.. It has various species like Nigrum, Melongenna, tuberosus, etc.
It is clear that, if I refer to Genus Solanum, I may be referring to any of these species.
This condition is LESS SPECIFIC and MORE GENERAL
But, If I particularly refer to a species eg: Nigrum... Ultimately this condition get you MORE SPECIFIED/ NO GENERAL.
Coming to our question, LESS GENERAL (means more specified) when compared to genus is species only and not any other one.
.
Thank You.