What is the fate of the primary xylem in a dicot root showing extensive secondary growth?

1. It is retained in the center of the axis

2. It gets crushed

3. May or may not get crushed

4. It gets surrounded by primary phloem

 

 
 
(a) Primary xylem is present in the centre of the root. As secondary growth occurs in the root the primary phloem is pushed outside whereas, primary xylem remains inside of the root.