Answer:
Individualistic
Step-by-step explanation:
Individualistic mindset focuses on the individual and gives them more emphasis than the group.
The opposite of individualism is collectivism or group mentality which emphasise the group over the individual.
To discuss the merger between the two companies, ABC company only sent one person while XYZ company sent 5 people from different departments.
ABC is most likely have a individualistic mindset and they feel one person can handle the negotiation.
On the other hand XYZ sent representatives from each department. This shows the organisation has to agree to the deal so all departments are involved.