Which `beta`-keto acid shown will not undergo decarboxylation?

Which of the following beta -keto carboxylic acid does not undergo decarboxylation on heating ?

A dicarboxylic acid of the form does not undergo decarboxylation on strong heating rather gives anothr stable product of molecular weight 100. Identify n.

Which of the following will undergo decarboxylation easily?

Which one of the following acids undergoes decarboxylation on strong heating: