The correct option is B Anton von Leeuwenhoek, Robert Hooke, Schleiden, Schwann, Virchow
Antonie Philips van Leeuwenhoek was first to observe the living cell. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist. He is best known for his work on the improvement of the microscope and for his contributions towards the establishment of microbiology.
The cell was first discovered by Robert Hooke in 1665, which can be found to be described in his book Micrographia. In this book, he gave 60 observations in detail of various objects under a coarse, compound microscope. One observation was from very thin slices of bottle cork. Hooke discovered a multitude of tiny pores that he named "cells".
Cell theory was eventually formulated in 1838. This is usually credited to Matthias Schleiden and Theodor Schwann. Cell theory has become the foundation of biology and is the most widely accepted explanation of the function of cells.
Virchow is credited with many important discoveries. His most widely known scientific contribution is his cell theory, which built on the work of Theodor Schwann. He was one of the first to accept the work of Robert Remak, who showed the origins of cells was the division of pre-existing cells.