Answer:
The correct option is: D. Strong acid
Step-by-step explanation:
The acid dissociation constant, also called the acid-ionization constant, is the strength of a given acid in a solution. It is a quantitative property which is denoted by the symbol Ka.
The negative logarithm of the acid dissociation constant i.e. the Ka value is equal to pKa.
pKa = -log Ka, where pKa and Ka are inversely proportional.
Therefore, for a strong acid, the acid dissociation constant, Ka is very large positive value and pKa is a negative value (pKa < 0).