The correct answer is (b) (ii) and (iii).
Explanation:
Involuntary muscles are those that are not under conscious control. Smooth muscles and cardiac muscles are considered involuntary because their contractions are not consciously regulated. Smooth muscles are found in the walls of internal organs like the stomach, intestines, and blood vessels. Cardiac muscles are found in the heart and are responsible for its rhythmic contractions.
Why other options are incorrect:
(a) (i) and (ii):
While smooth muscles are involuntary, striated muscles can be both voluntary and involuntary. Skeletal muscles, which are a type of striated muscle, are voluntary, meaning we can consciously control their movements.
(c) (iii) and (iv):
As mentioned before, cardiac muscles are involuntary, but skeletal muscles are voluntary.
(d) (i) and (iv):
This option is incorrect because both skeletal muscles (striated) and cardiac muscles are not entirely involuntary.