The correct option is:(a) 1 2 3 4
Explanation:
Living fossils are those organisms whose close relatives are not living on the earth. Cycas is a living fossil. Zamia pygmaea is endemic to Cuba and is the smallest gymnosperm on the earth. Sequoiadendron giganteum is the tallest coniferous gymnosperm known as redwoods. Canada balsam is obtained from the Abies balsamea (a North American fir) also known as Canada balsam.
