Hello there! :)
My name is ☆ Rain ☆ And I'm here to help you understand this better!
-----------------------------------------------------------------------------------------------------
Answer:
☆ Option A. (Many genes) ☆
Step-by-step explanation:
It happens because the chromosomes are made up of DNA, which carries a lot of genes. If the person misses a chromosome,it means that they also miss a part of the DNA that was supposed to be present in that missing chromosome. Each chromosome has different gene pools, so when one chromosome is not there then those genes will also be missing.
☆ Hope this helps! ☆
-Have an Awesome day!