Question

what is the main idea of \a conversation with a special effects expert\?
practical effects are always better than cgi because they are much more realistic.
cgi and practical effects are both used to make movies, but filmmakers use them differently.
filmmakers make detailed plans, so they know when to use cgi and practical effects.
the invention of cgi has led to many filmmakers using expensive practical effects less often.

Explanation:

To determine the main idea, we analyze each option:

• The first option makes an absolute claim ("always better") which is unlikely to be a main idea as it's too extreme.
• The second option states both are used but filmmakers use them differently, but this is more about their usage difference rather than a main idea about planning.
• The third option (selected) says filmmakers make detailed plans to know when to use CGI and practical effects. This aligns with a main idea about the planning process for using these effects.
• The fourth option claims CGI led to less use of practical effects, which is not supported as a main idea without more context, and the focus is on planning in the selected option.

Answer:

Filmmakers make detailed plans, so they know when to use CGI and practical effects.