An 85-Year-Old Patient's Blood Gasses Are as Follows: PH 7

An 85-year-old patient's blood gasses are as follows: pH 7.4,PaO₂ 75 mmHg,PaCO₂ 38.A patient's brain natriuretic peptide (BNP) was elevated on admission from the emergency department.Two days later,it has been reduced by half.What explanation of these findings by the nurse is best?

A) "It shows your heart failure may be resolving."
B) "Your heart is pumping much better now."
C) "The ventricles can relax to hold more blood."
D) "Your heart attack was not too serious."