This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
On thyroid function test, TSH value is raised and
t4 value is decreased. Referred diagnosis is 
Select and explain. 
A. Hyperthyroidism, B. Primary hypothyroidism, C. Secondary hypothyroidism, D. Subclinical hypothyroidism
B: Primary hypothyroidism
Answer: B: Primary hypothyroidism 
Explanation: IF TSH raised ans T4 is decreased then its primary.
IF both are decreased then its secondary.