A human's wavelength is similar to the size of:
a) a cell
b) atom
c) nucleus
d) proton
e) something else
and why?
Here is a very very very loooong answer for you (but it's very well done). You can skip to the last two lines and get your answer but if you read all of it you will summarize a lot of physics/chemistry/wave/particle information.
http://www.physlink.com/education/askexperts/ae307.cfm
A human's wavelength is actually much larger than a cell, an atom, a nucleus, or a proton. Wavelength is a property typically associated with waves, such as light waves or sound waves. It represents the distance between two corresponding points in a wave, such as from one peak to another peak.
In the context of humans, we don't typically talk about wavelengths. Instead, we often refer to the size of a human or parts of a human in terms of length or scale.
For example, a human's height can be measured in meters or feet. The average adult human is several feet or meters tall.
Therefore, the correct answer among the options provided would be "e) something else" since the wavelength of a human is not comparable to any of the options given.