Data Sufficiency

sales of company A in 2005 = SA5
sales of company A in 2006 = SA6
sales of company B in 2005 = SB5
sales of company B in 2006 = SB6
percent of sales of company A increase = (SA6 - SA5) * 100 / SA5

From 1, we can know SA5 = 0.25 * SB5
as we don`t know value of SA6 and SB5. we can`t answer using this alone.

From 2, we can know SA6 = 0.25 * SB6
as we don`t know value of SB6, we can`t answer using this alone.

From 1 and 2 also we can`t get values of SA6 in terms of SA5. AS we don`t know SB6 in terms of SB5 or their values to get the values.

Hence, it is E