European visitors to ming china in the sixteenth century were

The Ming Dynasty started European trade and cultivated relations with European powers. The dynasty traded with the Portuguese, the Spanish, and the Dutch, who all established trading bases near Guangzhou (like Macau). The Europeans had great demand for Chinese goods, especially porcelain and silk, which they paid by silver (the Chinese esteemed silver more than gold). 

i think the answer is a and i hope this ; ))

it was bribing i think i might be wrong though