Answer: B
Correct answer: A few short lines, with the detail spoken rather than written
A slide should carry a few short lines. The detail belongs in what the speaker says and in the handout, not on the screen. The reason is cognitive rather than aesthetic. An audience cannot read and listen at the same time: presented with a dense slide, they read it - faster than the speaker can talk - and then stop attending. A slide crowded with text therefore competes with the presenter rather than supporting them. Various rules of thumb encode this, such as the 6×6 guideline of at most six bullets of six words, or the 1-6-6 variant. None is a law, but all point the same way. The practical consequences are that font size should not be reduced to fit more in - if it does not fit at a readable size, it belongs elsewhere - and that a slide is better carrying one idea than several. Speaker notes exist precisely so the detail need not be on the slide.