My boss will travel to China from 13th Nov to 20th Nov, do a Business visa required?

if your boss has the invitation letter from China side, the business visa is the best choice for her to apply. You can book her flight now, you'd better book a refundable flight tickets, if her application is denied, you can countermand the ticket.

Dear Sir or Madam

According to the information I read it is sufficient for a Belgian citizen to have the ticket reservation as well as hotel reservation in order to apply for a VISA type business.

Is this also a must to have an invitation letter as I understood that the traveller could choose from the options: ticket reservation & hotel resevation OR recommendation letter.

Please advise

Maria Luisa, the applicants who apply for F-visa with single or double entries should provide (A) the return flight ticket and the booking document of hotel in China, or (B) visa notification issued by an authorized unit in China (a visa notification form refers to the form of visa notification issued by the Chinese governmental departments, companies and social organizations authorized by the Chinese Foreign Ministry), or (C) letter of invitation issued by a state-owned enterprise, collectively-owned enterprise joint venture, solely-owned or private enterprise, or (D) invitation cards of various kinds of trade fairs or GuangDong Trade Exibhihitions.

You can choose from the above 4 options.