The sentence is not framed correctly though....
Can you explain ? I felt the answer should be D.
The question asks for a statement that will not only justify Leona's claim but also refute Thomas's claim.
Part I - It is ok to say 5,000 people are saved as long as they (the same 5,000 people) don't die due to consumption of eggs
This part proves Leona's claim to be true.
Part II - Those 5,000 people could die due to other reasons.
This part refutes Thomas's claim that the population will be 50,000 more in 10 years.