The answer is option (d). (1 mark)
Some organisms live together and share shelter and nutrients. This kind of association is termed as symbiotic relationship or symbiosis.
One of the following organisms has a saprophytic mode of nutrition. This organism is : (a) mushroom (b) malarial parasite (c) leech (d) lice
Two organisms are good friends and live together. One provides shelter, water, and nutrients while the other prepares and provides food. Such an association of organisms is termed as: