GRE Text Completion: Manhatton-GRE填空Manhatton - B218B1G1S26416UF=

As an evolutionary adaptation, cats have developed a mechanism whereby their heads are measuring devices, as their bodies can fit through any space that their heads can, and this physiology is a safeguard that ____________ their success as a species. A. reproduces B. ensures C. enhances D. mitigates E. inundates