Decreased blood flow due to limiting the amount of blood
Homozygous.
You can tell in future that if both letters are either lowercase or upper case (e.g. TT or tt) the answer is always HOMOzygous. If the letters are different cases (e.g. Tt or tT) the answer is always HETROzygous. This is because 'homo' means 'same' and 'hetero' means 'different'.
18% of 400 is 72
Hope it helped