The correct answer is "option 4".

CONCEPT:

The components of the Memory tube display are:

1. Flooding gun

2. Collector

3. Ground

Hence, Liquid crystal is not a component of the Memory tube display.

1.There are two types of guns in the Memory tube display: Primary gun and flooding gun.

2.Some other components of Memory tube display are:

a. Writing beam

b. storage grid

c. Screen

d. Focusing & deflection system

e. Flood electron

f. Ground/base