Two Scientists Working in the Field Discover a Small Slug-Like

Two scientists working in the field discover a small slug-like creature which is approximately 1mm long. The two scientists disagree on the origins of the organism: one believes it to be a true mollusc, the other suspects it could be a pseudoplasmodium. How could it be most simply determined what the true nature of the organism is?

A) Place the 'slug' in an environment favourable to cellular slime moulds with sufficient food sources and observe if the slug differentiates into a fruiting body.
B) Perform DNA analysis and look for molecular markers specific to molluscs.
C) Dissect the slug under microscopy and analyse the internal anatomy of the organism.
D) Place the 'slug' in an environment favourable to cellular slime moulds with sufficient food sources and observe if the slug differentiates into a mass of individual amoeba.
E) Using a classical Linnaean system, use physiological and morphological features to key out the organism to genus and species.