One little helpful trick here is to try and figure out an explanation even before you read the options.
Why would there be many more tourists to aquariums than to zoos? maybe because there are more zoos for the locals to visit.
If a family has one aquarium close to home and two zoos it makes sense for them to visit the aquarium one time a year, and each of the two zoos one time. Resulting in a bigger number of locals visiting zoos.
Or another explanation could be that the zoo changes animals more often so it makes more sense for locals to go visit more often.
If you scan the options and find one that s coherent with your train of thoughts (like in this case) then you are in a good spot.
"The Burnout" - My Debrief
Kudos if I helped you