Hi Cherise,
The author states that after ownership is transferred, the full set of rights is "not necessarily transferred to the new owner" (Lines 18-19) and that "the original owner may retain one or more of these rights." (Line 20)
Notice how the author qualifyies both of these statements. We are not being told that the right to copy a product for profit
must be retained, but rather that the original owner is
allowed to retain the rights. Later in the second paragraph, we learn that the original owner "typically" retains the right to copy the object for profit.
What this tells us is that there is the possibility of transferring these rights to the new owner, and the possibility of the original owner retaining the rights. Answer choice (C) states that we can infer that "the idea that ownership of the right to copy an item for profit
can be transferred" is compatible with the tangible-object theory. Since the author discusses retaining this right as optional in the theory, then both retaining this right and transferring this right are compatible with the theory.
Let me know if this helps!