I'd say b, precise, here.
If there's an error somewhere in the experiment or project, then it is consistently .... wrong. So, just 'cos you measure something precisely, it doesn't mean that you've measured it accurately. Maybe an example would be a measurement of length. If you used a metal ruler at zero degrees C, you can measure to say half a millimetre. A series of measurements of the same object would give very similar readings. But, if you used same metal ruler at, say 100 celsius (implausible) then you'd probably get a different set of readings. 'cos of the expansion of the metal ruler.
Answer:
Most of the stars occupy the region in the diagram along the line called the main sequence. During the stage of their lives in which stars are found on the main sequence line, they are fusing hydrogen in their cores.
D. they have a full luster
