Final answer:
The contractile vacuole in Paramecium is presumed to be a precursor of the lysosome due to its role in osmoregulation and waste removal, which is functionally similar to lysosomal activities in eukaryotic cells.
Step-by-step explanation:
The contractile vacuole is an organelle found in certain unicellular organisms, like Paramecium, and is presumed to be a precursor of the lysosome. The function of contractile vacuoles involves the excretion of excess water from the cell, thereby maintaining osmotic balance. This is similar to the role of lysosomes in eukaryotic cells, which involves the digestion and waste removal within the cell. Contractile vacuoles perform a key osmoregulatory function, which is analogous to lysosomes' role in intracellular digestion and waste processing. During a hypotonic medium where water diffuses into the cell, a paramecium's contractile vacuole continuously pumps excess water out to prevent the cell from bursting.
In the experimental investigation mentioned, Paramecium were placed in salt solutions of different osmolarities, and the activity of the contractile vacuoles was measured. As osmolarity increased, the rate of contraction of the vacuoles likely increased as well to remove the excess water entering due to the osmotic gradient, showing the organism's regulation of water balance.
Lysosomes in plant cells are not present in the same form as in animal cells but their function is somewhat carried out by large central vacuoles that also manage storage and waste disposal, among other functions. Whereas lysosomes and peroxisomes are both types of organelles involved in various cellular processes including degradation of macromolecules. Hence, the correct answer to the question is D) Lysosome.