NPC DAMAGE TYPES (TANK):
Guristas - Bananas(95%)/Apples(5%)
Serpentis - Apples(50%)/Bananas(50%)
Blood Raider - Oranges(50%)/Apples(50%)
Sansha's Nation - Oranges(60%)/Apples(40%)
Angel Cartel - Bananas(35%)/Pineapples(50%)/Apples(10%)/Oranges(5%)
EoM - Bananas(85%)/Apples(15%)
Rogue Drones - Bananas(35%)/Pineapples(50%)/Appeles(10%)/Oranges(5%)
Mercenary - Oranges(35%)/Apples(35%)/Bananas(15%)/Pineapples(15%)
The Seven - Pineapples(35%)/Bananas(35%)/Apples(15%)/Oranges(15%)
Mordu Legion - Bananas(60%)/Apples(40%)

NPC RESISTANCES (WEAKNESSES):
Guristas - Bananas(45%)
Serpentis - Bananas(45%)
Blood Raider - Oranges(45%)
Sansha's Nation - Oranges(45%)
Angel Cartel - Pineapples(45%)
EoM - Bananas(40%)
Rogue Drones - Oranges(40%)
Mercenary - Apples(35%)
The Seven - Apples(30%)
Mordu Legion - Apples(45%)/Bananas(45%)

mission running guides

https://eveinfo.com/missions/4/level-four/ (note) Very helpful!