Hugo deVries's work on mechanism of evolution states that evolution is

The correct answer is Option (3) → caused due to a single step large mutation

Option (1) a multi-step process — Incorrect. He said evolution is a single step, not a multi-step process.

Option (2) based on minor variations — Incorrect. Minor (heritable) variations were what Darwin talked about. de Vries believed it is mutation, not these minor variations, that causes evolution.

Option (3) caused due to a single step large mutation — Correct. Hugo de Vries, working on the evening primrose, said that evolution is caused by mutation, not by small gradual variations. He called a single step large mutation that causes speciation saltation.

Option (4) directional and continuous process — Incorrect. For Darwin, variations were small and directional and evolution was gradual. de Vries held that mutations are random and directionless and arise suddenly, so this is not his view.

NCERT Extract:
Mechanism of Evolution – “… In the first decade of twentieth century, Hugo deVries based on his work on evening primrose brought forth the idea of mutations – large difference arising suddenly in a population. He believed that it is mutation which causes evolution and not the minor variations (heritable) that Darwin talked about. Mutations are random and directionless while Darwinian variations are small and directional. Evolution for Darwin was gradual while deVries believed mutation caused speciation and hence called it saltation (single step large mutation).”