Final answer:
Disruption of nuclear pore complexes primarily affects the transport of mRNAs from the nucleus to the cytoplasm, which is essential for protein synthesis.
Therefore, the correct answer is a. mRNAs.
Step-by-step explanation:
Disruption of nuclear pore complexes in a eukaryotic cell will most likely interfere with the transport of mRNAs into the nucleus. The nuclear pore complexes are crucial for the transport of large molecules such as mRNAs, tRNAs, and ribosomal subunits across the nuclear envelope. Specifically, mRNAs, which are transcribed from DNA in the nucleus, must pass through these pores to reach the cytoplasm where they are translated into proteins. Nuclear pore complexes facilitate the exit of mRNA from the nucleus into the cytoplasm, and are also essential for the import of ribosomal proteins that are manufactured in the cytoplasm and needed within the nucleus.