[单选题]
Light of wavelength 5a 9ir38a+ khwx00 a1c.r l2v9l;x;luqg unm illuminates a soap film ( n = 1.33). What is the miniu1g;q2 xv.lclru al 9;mum thickness of film that will give an interference when the light is incident normally on it?
A. $24 \; nm$
B. $94 \; nm$
C. $188 \; nm$
D. $376 \; nm$
