UK visa application: What visa type do I need to select?

That sounds like a clear business visit.

According to appendix 3 of the visitor rules:

Business – general activities

5 A visitor may:
(a) attend meetings, conferences, seminars, interviews;
(b) give a one-off or short series of talks and speeches provided these are not organised as commercial events and will not make a profit for the organiser;
(c) negotiate and sign deals and contracts;
(d) attend trade fairs, for promotional work only, provided the visitor is not directly selling;
(e) carry out site visits and inspections;
(f) gather information for their employment overseas;
(g) be briefed on the requirements of a UK based customer, provided any work for the customer is done outside of the UK.

Business – corporate*

Intra-corporate activities

6 An employee of an overseas based company may:
(a) advise and consult;
(b) trouble-shoot;
(c) provide training;
(d) share skills and knowledge; on a specific internal project with UK employees of the same corporate group, provided no work is carried out directly with clients.

7 An internal auditor may carry out regulatory or financial audits at a UK branch of the same group of companies as the visitor’s employer overseas.

If you do work that do not fall under this or one of the other exceptions in appendix 3, you will need a different kind of visa that may be hard to get. In that case your company should be paying someone for proper legal guidance.