Just who inspired English painter John Constable's marvelously enigmatic cloud studies, much prized by collectors have never been entirely clear.

Just who inspired English painter John Constable's marvelously enigmatic cloud studies, much prized by collectors have never been entirely clear.

• ক. studies, much prized by collectors, have
• খ. studies, much prized by collectors, has
• গ. Studies, many of them prized by collectors, have
• ঘ. studies, many of which are prized by collectors,