Select the chemical fluid or substance from the options below that has a $\text{pH}<7$:

On the standard $\text{pH}$ scale, values less than $7$ denote acidic substances. Lemon juice is rich in citric acid and typically possesses a highly acidic $\text{pH}$ value ranging between $2.0$ and $3.0$. In contrast, human blood ($\approx 7.4$), lime water (${\text{Ca(OH)}}_2$), and antacids are chemically basic ($\text{pH}>7$).