Fact 1: Secondary growth forms secondary vascular tissues and bark.

Fact 2: All trees have bark.

Given the two facts above, answer the question "What forms secondary vascular tissues in trees?" with the following options: 
- allow growth
 - primary growth
 - secondary growth
 - In their leaves
 - end growth
 - mating
 - Most plants
 - shrub beds


 

   secondary growth      