This presumptive blood test uses phenolphthalein and turns pink when exposed to blood. Select one: a. Luminol b. Kastle-Meyer c. Precipitin d. Microcrystalline e. Hemastix

## Step 1<br />The problem is asking us to identify a presumptive blood test that uses phenolphthalein and turns pink when exposed to blood. <br /><br />## Step 2<br />The Kastle-Meyer test is a presumptive blood test that uses phenolphthalein. When the test reagent is sprayed on a surface suspected of having blood, it will turn pink if blood is present. This is because the phenolphthalein in the reagent reacts with the iron in hemoglobin, a component of blood, to produce a pink color.<br /><br />## Step 3<br />The other options provided, Luminol, Precipitin, Microcrystalline, and Hemastix, are also tests used in forensic science, but they do not use phenolphthalein and do not produce a pink color when exposed to blood.