Which of the following is true about Alkalis?

Q. Which of the following is true about Alkalis?

1. Bases which are soluble in water are called alkalis
2. Bases which are soluble in acids are called alkalis
3. Bases which are soluble in other bases are called alkalis
4. Bases which are harsh to touch, sour in taste are called alkalis

Answer: Bases which are soluble in water are called alkalis