Why might it be difficult to classify some slime molds as unicellular or multicellular. Explain

Because some people define a multicellular organism as that of not being able to live and propagate if it is taken outside of itself. For e. g. if you take a human leg, then two humans are not going to form (i. e. a human is not going to form out of the leg, and the other human to get it's leg back). So in that sense a mold is more 'unicellular' in that the cells do not depend on each other for survival. However, it's also multicellular in the sense that they form 'one body' that has a 'single function' ... but if you were to take a piece of mold away then it could regenerate into more mold ... and a single cell could survive on it's own.