Aresearcher finds a that people who own more than two cars have bigger homes, more garage space and make more money than people who own one or two cars. her inference that having more than two cars causes people to have homes with bigger garages is lacking which type of causal evidence?

Her inference is lacking elimination of alternative explanations.
This researcher only mentioned one explanation for this issue and that is having more than two cars. She doesn't account for other explanations and causes for this to happen - she doesn't give alternatives, which is why her inference is lacking and should not be trusted. 

Pilgrims is the answer