Choice A rationale:

"Increased platelet production due to chemotherapy." Rationale: This statement is not accurate.

Chemotherapy often suppresses bone marrow function, leading to a decrease in platelet production, not an increase.

Thrombocytopenia is a common side effect of chemotherapy due to reduced platelet production.

Choice B rationale:

"Immune-mediated platelet destruction caused by chemotherapy." Rationale: This statement is correct.

Thrombocytopenia in patients undergoing chemotherapy is often due to immune-mediated platelet destruction.

Chemotherapy can trigger an autoimmune response, leading to the destruction of platelets by the immune system.

Choice C rationale:

"Thrombocytopenia in this case is unrelated to chemotherapy." Rationale: This statement is unlikely to be true.

Thrombocytopenia occurring in a patient following chemotherapy is often directly related to the treatment.

While other factors may contribute, chemotherapy is a known cause of decreased platelet counts.

Choice D rationale:

"Thrombocytopenia results from the inhibition of platelet aggregation by chemotherapy." Rationale: This statement is not accurate.

Chemotherapy primarily affects platelet production and can lead to a decrease in platelet count.

It does not typically inhibit platelet aggregation.