d Answer:Litmus and china rose ,both are natural indicators.Explanation:First of all, let us understand what exactly indicators means!❒ Indicators are those substances that are used to recognize whether the substance is acidic or basic in nature.❒ Indicators change their colour on COMING in contact with the substance we want to test.❒ Natural Indicators :☛ Made from the substances found in our nature like leaf, FLOWERS etc.☛ Examples : Litmus, china rose, TURMERIC.❒ Synthetic Indicators :☛ Made from dyes in laboratories and factories.☛ Examples : Phenolphthalein, Methyl orange.Now from these information , let us verify our answer!Option A ( Turmeric and Phenolphthalein )→ According to the question, we have to select the option that must have both natural indicators.• Here, turmeric is a natural indicator as it is obtained from nature.• But phenolphthalein is a synthetic indicator.Thus, this option is wrong.Option B ( Litmus and hydrochloric ACID )→ Here,• Litmus is a natural indicator because it is obtained from lichens present in biome.• But HCL is an acid not an indicator. So, it is neither a natural indicator nor a synthetic indicator.Thus, this option is wrong.Option C ( China rose solution and baking powder)→ Here,• China rose is a natural indicator as it is obtained from nature.• But baking powder isn't an indicator, it is a base. So, it is neither a natural indicator nor a synthetic indicator.Thus, this option is wrong.Option D(Litmus and china rose solution )→ Both litmus and china rose (hibiscus) solution are indictors as litmus is extracted from lichens present in our nature and china rose from hibiscus plant.Thus, this option is CORRECT. ✔