20 Choose the best description with respect to an inventor:
(A) An inventor can be a nature person, a company or a legal entity of another type.
(B) A researcher only executing results testing can be deemed to be an inventor, because the testing
requires some special skill and experience.
(C) All joint inventors have to make an equal contribution to an invention.
(D) An inventor is a person who has made substantial contribution to the technical features of patent
claims.