Because of strong overall stylistic similarities, prehistoric cave paintings in El Castillo, Spain and others in Altamira, Spain, were thought to date from the same period. Recent pigment analyses, however, established the Altamira paintings as by far the older and as about the same age as a third group of paintings done in a different overall style. Nevertheless, this case does not prove that stylistic similarities cannot be a reliable indicator of closeness in age, since __. Which of the following most logically completes the passage? ['Determining the age of a prehistoric cave painting simply by reference to the age of the pigments used in that painting substitutes technology for artistic judgment', 'Experts who knew the results of the pigment analyses reexamined these paintings and found no previously unnoticed stylistic similarities between the Altamira paintings and the paintings in the third group', 'There are experts who maintain that the results of the recent pigment analyses leave the striking stylistic similarities between the El Castillo paintings and the Altamira paintings unexplained', 'There are certain stylistic features that the Altamira paintings share with all known paintings of their period and do not share with the El Castillo paintings']