The pyramid of numbers is always upright. If it changes ………
i) the number of producers will be more in the trophic level.
ii) a tree is the producer.
iii) it is always upright. Change does not occur.
iv) Producers are at the base only though the pyramid is in any form.
A) i only
B) i, ii, iii
C) i, ii, iv
D) All are correct
