C can be taken out of the question as eukaryotic cells do not have a nucleus. A lysosome is is only in prokaryotic cells so B can be taken out of the question. The answer should be D.
<span>Species because it narrows it down to one thing.</span>
<span>You
are right in that bananas contain potassium and K-40 is a naturally
occurring potassium isotope AND the K-40 in an average banana does decay
at a rate of about 31 ATOMS per second (half-life is > 1 billion
years). This is an extremely low level of radiation and nothing to worry
about. Bananas will definitely NOT cause a "nuclear winter."</span>
