What is the only means of preserving beauty, according to these lines from William Shakespeare's Sonnet 3?

Thou art thy mother's glass, and she in thee
Calls back the lovely April of her prime:
So thou through windows of thine age shall see
Despite of wrinkles this thy golden time.
But if thou live, remember'd not to be,
Die single, and thine image dies with thee.

Question

What is the only means of preserving beauty, according to these lines from William Shakespeare's Sonnet 3?

Thou art thy mother's glass, and she in thee
Calls back the lovely April of her prime: 
So thou through windows of thine age shall see
Despite of wrinkles this thy golden time. 
But if thou live, remember'd not to be, 
Die single, and thine image dies with thee.

anonymous · Answer

memory
procreation
praise
art