Donor States

Donors have been added to a semiconductor to make it n-type (assume ND >> ni ).  The band diagrams below are snapshots of the doped semiconductor at different temperatures.  Do you know what we mean by snapshots?

Which of the band diagrams below is at:
(Choose a temperature for each situation.)

0K 50K 300K 500K NEVER
 a.) 
0K 50K 300K 500K NEVER
 b.)
0K 50K 300K 500K NEVER
 c.) 
0K 50K 300K 500K NEVER
 d.) 
0K 50K 300K 500K NEVER
 e.) 
0K 50K 300K 500K NEVER
 f.) 

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