Cell is the basic structural unit of the body. Membrane is a structural component that separates intracellular and extracellular environment by means of plasma membrane. This cell membrane allows movement of material, cargo in and out of the cell, gives protection and communication with external environment.
Inside the eukaryotic cell (nucleus having), numerous cell organelles such as chloroplast, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, ribosomes, nucleus, etc. are present, which serve various functions.
Thus, the options (a), (c) and (d) are incorrect.
Cell is the basic structural unit of the body. Membrane is a structural component that separates intracellular and extracellular environment by means of plasma membrane. This cell membrane allows movement of material, cargo in and out of the cell, gives protection and communication with external environment.
Therefore, the correct option is – b. cell membrane.