the biggest threats to christmas island crabs during their annual migration are ______.\na. dogs\nb…

Brief Explanations:

During the annual migration of red crabs on Christmas Island, millions of crabs move from the forest to the ocean to breed. This journey requires them to cross numerous roads. Historically, automobiles (traffic) posed the most significant direct threat, leading to high mortality rates from being crushed. To mitigate this, local authorities now implement road closures and have constructed specialized crab bridges and underpasses. While invasive yellow crazy ants are a major biological threat to the population overall, among the options provided regarding the physical migration journey, vehicles are the primary hazard.

Answer:

c. automobiles