in 1492,Columbus and his crew arrived ___was so called the N

不能,答案是：in what.
1.根据句意和结构可知,what was so called the New World by the westerners为介词in的宾语,即宾语从句.
arrive是不及物动词,不能直接加宾语（从句）,所以必须先加一个介词in（the New World为大地方,所以用in最合适）.
2.该宾语从句明显缺少表示事物sth的主语,所以用what代替并引导此从句.
which一般用于定语从句,但是此时从句前面没有表示地方的名词/代词即没有先行词,排除；
which如果引导宾语从句,则其意思是“哪一个/些”,则该从句前后必须有限定的范围方可,排除.如：I wonder which you like best of all these colors.其中of all these colors即为限定范围.

In 1492 Columbus and his crew arrived_ was so-called the New World D。不能选WHERE。因为ARRIVE是不及物。要加 IN接地点。IN后WHAT 引导了一