The only answer that is not an example of a cell specialization is :
<span>Bacteria cells are small in size in order to easily diffuse in and out of the cytoplasm.
All of the other examples, the muscle, nerve and the rod and cone cells have specific cell structures, shapes, and proteins that enable them to execute their specific roles in the organism. </span>
The correct answer is postural muscles.
Postural muscles are muscles with the function to sustain posture in the gravity field. In response to stimuli such as over-use, under-use or trauma, postural muscles tend to shorten. This type of muscles is sometimes called tonic muscles because they have high resting tonus.
Surprisingly chocolate actually contains a fair amount of iron. Red meats are known to contain iron, one thing in particular is blood (yes that is sometimes eaten, and it contains a lot of iron). Such organs of animals that are high in iron include the spleen and or marrow.
If you wish to go vegetarian red veggies tend to be high in iron, one in particular are beets (yes, i know, they aren't red until processed)