What does it mean to be gleamed like pearls?

Avery thin (As he never ate much, his arms were as thin as a rake)

Bvery thin (This path is as thin as a rail)

Cvery red (These fresh tomatoes are as red and shiny as rubies)

Dshining very brightly (Amazed by the sight of the famous singer, the little children's eyes gleamed like pearls)