$9.$ The main reason why clinker phases, such as alite, belite, aluminate, andferrite, react when mixed with water is that these are...

a$)..$stable crystals that react in water.

b$)$ defective crystals that react readily in water.

c$)$ defective crystals with high amounts of network formers.

D$)...$ defective crystals, mainly classified as inosilicates.

$10.$ Cementitious Materials $($SCMs$),$ such as fly ash, slag, clays, are useful because of the following reasons, EXCEPT:

a$)$ Aid in the compressive strength development of concrete

b$)$ Generally improve durability properties

c$)$ Accelerate the hardening rate of concrete

D$)$ Reduce the environmental impact of concrete by reducing the use of portland cement