Find the moment-generating function of the negative binomial distribution by making use of the fact that if

Question:

Find the moment-generating function of the negative binomial by making use of the fact that if k independent random variables have geometric distributions with the same parameter θ, their sum is a random variable having the negative binomial with the parameters θ and k.
Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...