Express the following quantities to the correct number of significant figures:

(a) 23.043 ± 4.321
(b) 67 ± 9.023
(c) 33.1492934 ± 2

Isn't (a) already the correct number of significant digits?
Would (b) be 67.000 ± 9.023?
Would (c) be 33.1492934 ± 2.0000000

or would
(a) 23.04 ± 4.321
(b) 67 ± 9.0
(c) 30 ± 2

2 answers

b) you cant add precision to 67

67+-9
c) it is correct as written.
which of the a answers are right?
and which of c?