Sometimes sound and uninjured seeds may fail to germinate due to reduced activity of the seed or seed parts resulting in blockade of the growth. This may be due to:

A. External effects of environment
B. Internal conditions within the plant itself, i.e. Embryo dormancy or seed coat dormancy
C. Both (a) & (b)
D. None of these

Tingling purpose is / are:

A. Sanitation: To protect from pest and diseases
B. Spacing
C. Removing of destroyed trees for sale
D. All of the above