The oxidative phase of the pentose phosphate pathway
a. reversible under physiological conditions.
b. has an enzyme requiring thiamine pyrophosphate as a coenzyme.
c. produces ribulose‑5‑phosphate and nadph for biosynthetic processes.
d. converts pentoses to hexoses.

C: Produces ribulose-5-phosphate and NADPH for biosynthetic processes.

Explanation:

There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars. For most organisms, the pentose phosphate pathway takes place in the cytosol; in plants, most steps take place in plastids.

6.4 cm (max) - 25 cm (min)

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.