The correct order of decreasing acidity of the following aliphatic acids is:

$\displaystyle \left(\mathrm{CH}_3\right)_3 \mathrm{CCOOH}>\left(\mathrm{CH}_3\right)_2 \mathrm{CHCOOH}>$ $\displaystyle \mathrm{CH}_3 \mathrm{COOH}>\mathrm{HCOOH}$

$\displaystyle \mathrm{CH}_3 \mathrm{COOH}>\left(\mathrm{CH}_3\right)_2 \mathrm{CHCOOH}>$ $\displaystyle \left(\mathrm{CH}_3\right)_3 \mathrm{CCOOH}>\mathrm{HCOOH}$

$\displaystyle \mathrm{HCOOH}>\mathrm{CH}_3 \mathrm{COOH}>$ $\displaystyle \left(\mathrm{CH}_3\right)_2 \mathrm{CHCOOH}>\left(\mathrm{CH}_3\right)_3 \mathrm{CCOOH}$

$\displaystyle \mathrm{HCOOH}>\left(\mathrm{CH}_3\right)_3 \mathrm{CCOOH}>$ $\displaystyle \left(\mathrm{CH}_3\right)_2 \mathrm{CHCOOH}>\mathrm{CH}_3 \mathrm{COOH}$