In a deductively valid argument, given true premises, the conclusion ... a. Follows with certainty (necessarily). b. Probably follows. c. Does not follow.

a. Follows with certainty (necessarily)

Explanation:

In a deductively valid argument, if the premises are true, then, the conclusion is necessarily true. It is impossible for a deductively valid argument to have false premises and and a true conclusion, or to have true premises and a false conclusion. It would not make sense.

An example of this type of argument would be:

If it rains, I will be carrying un umbrella. It's raining, therefore, I'm carrying un umbrella.