Answer: (a) basic
Turmeric is acidic in nature hence it is converted to red due to neutralization by the base.
Turmeric compound is a naturally occurring yellow colour compound. It is an acid-base indicator, turmeric compound remains yellow when acid or neutral solutions are added to it. When basic solutions such as sodium hydroxide are added to it, the solution turns pinkish-red.
A neutralization reaction can be defined as a chemical reaction in which an acid and base quantitatively react together to form a salt and water as products. The chemical equation of neutralization reaction is
acid + base(alkali) → salt + water