Fact 1: Most plants continue to grow throughout their lives.

Fact 2: Lilies continually produce new bulbs, from which grow new plants.

Given the two facts above, answer the question "What continues to grow throughout their lives? " with the following options: 
- potatoes
 - Hemoglobin
 - tortoises
 - plastic  roses.
 - Human teeth.
 - Lilies.
 - Silk daisies.
 - vegetation


 

      Lilies.   