Answer:
D. priming
Step-by-step explanation:
Priming - 
It is the process by which some external stimulus , like the image , person , word , changes the response of the person , is referred to as priming . 
This process takes place , specially during the stage of decision making , when some factors alters the decision of the person . 
Hence , from the given scenario of the question , 
Price of T shirt alters the decision of Joanna . 
The correct option is D. priming .