I wouldnt say that it has much to do with latitiude eventbkigh there are quite a few at both of the poles. It usually corresponds wirh altitude. There are glaciers in every continent.
I think it’s A (low water content foods)
Scientists will look for evidence like similar body or skeleton structures, internal similarities or maybe sometimes the whole heirarchy to confirm that two speices are closely related to each other.
For example ; in birds, scientists will look for type of feathers, body structure, beaks to confirm the similarity of two birds.