As we go from species to kingdom in a taxonomic hierarchy, the number of common characteristics  
(A) will decrease
(B) will increase
(C) remain same
(D) may increase or decrease a. will decrease   b. will increase   c. remain same   d. may increase or decrease

Sure, here are the step-by-step solutions: Given: A will decrease. Solution: 1. Let's assume that A has an initial value of $A_0$. 2. Since A will decrease, we can write: $A<A_0$. 3. We can also express this as: $A_0-A>0$. 4. Dividing both sides by $A_0$, we get: $\frac{A_0-A}{A_0}>0$. 5. Simplifying the left-hand side, we get: $1-\frac{A}{A_0}>0$. 6. Rearranging this inequality, we get: $\frac{A}{A_0}<1$. 7. Multiplying both sides by 100%, we get: $\frac{A}{A_0}\times 100\%<100\%$. 8. So, we can conclude that A has decreased by a percentage equal to: $(1-\frac{A}{A_0})\times 100\%$.