Need 2 know the correct answer as soon as possible. Thank u

There is only one true statement : a, b, c or d

Consider the following statements regarding the production sector of the beer...
Question 1. (switching costs = sunk costs)
a) the switching costs (due to the bargaining power of suppliers) only occurs with barrel providers. (I dont know if this one is true)
b) the switching costs are found in all formats of consumption. (this one is false because question c) is false)
c) the switching costs are only found in beer bottle or can. (false cause anyone can provide you cans and bottles)
d) the switching costs are not found in any format of consumption. (if question a) is false this one is true)

REMEMBER: ONLY ONE TRUE STATEMENT . THANK YOU VERY, VERY, VERY MUCH FOR YOUR HELP!!! BEST REGARDS, SARAH (petitgirl17@hotmail.com) If you dont mind, i need to know how you got the answers: references, statistics... because i need to be sure they are accurate. Thank you so much!!!!