Answer:
A set is continuos if the values of the set can be any value in the given ranges
A set is discrete if the values of the set are finite and separate.
Than:
a) The weight of a puppy.
The weight of a puppy can be any value between 0 kg and a given maximum weight, then this is a continuous set.
b) The number of puppies in a litter.
Here we can have only whole numbers, for example, we can not have 7.34321 puppies in the litter, so this is a discrete set.
c) A person's temperature.
Temperature can be any value in a given range, so this is a continuous set.
d) The dress sizes of women.
Normally, there is a given set of dress sizes like s, l, xl, etc.
So in general, this is a discrete set. (While the actual "size" of a dress can take a lot more values than those ones, but this still is a discrete set)