1 2 can't confirm that Xiao Wang has been hired. I must have been hired, but I didn't. So a is wrong.
Two truths and two lies. If 4 is true, then 1 is also true. Two-thirds of the introductions are false, so Xiao Wang is not hired, or C is wrong.
If 1 is false, it means that only one person has been hired, and 3/4 is false, then 2 is true, which means that Xiao Wang has not been hired, then 3 is false and 4 is true, which means that Xiao Chen is easily hired and Xiao Wang has not been hired.
B ok.