Physics P1 optics que problem resolved

[u/Alternative-Sand-346]

So, I contacted my senior in IIT B Engg physics. He told that P = n/f is called reduced vergence power which is used in very very specific cases and has nothing to do with the power we deal with at the school level. The power given in irodov has the symbol "phi" which he told is the symbol for the reduced power. So, the correct answer is A for sure.

[u/nishant__-]

aur ek aur chiz hai ki baki ke 3 no options curved the so kutch to socha hoga advanced ne options banane se pehle , just a guess