Mice, dogs, and tigers have:
All three options listed in the question are characteristics that do not apply to mice, dogs, and tigers. Mice, dogs, and tigers are all mammals, and as such, they share certain characteristics. The correct answer is option 'A', which states that they have fur and four legs.

Mammals:
Mammals are a diverse group of animals that share several common characteristics. Some of these characteristics include:

1. Fur or Hair: Mice, dogs, and tigers, like all mammals, have fur or hair covering their bodies. The fur helps to keep them warm, provides camouflage, and serves various other functions.

2. Four Legs: Mice, dogs, and tigers, like most mammals, have four legs. These legs enable them to walk, run, climb, and perform various other movements.

3. Live Birth: Mice, dogs, and tigers, like all mammals, give birth to live young. Unlike animals such as reptiles or birds, which lay eggs, mammals have internal fertilization and nourish their offspring within their bodies until they are ready to be born.

4. Mammary Glands: Mice, dogs, and tigers, like all mammals, have mammary glands that produce milk. This milk is used to nourish their young until they are old enough to consume solid food.

5. Warm-Blooded: Mice, dogs, and tigers, like all mammals, are warm-blooded animals. This means that they can maintain a relatively constant body temperature regardless of the external temperature.

6. Vertebrates: Mice, dogs, and tigers, like all mammals, are vertebrates. They have a backbone or a spinal column that provides support and protection for their internal organs.

Conclusion:
In conclusion, option 'A' is the correct answer because mice, dogs, and tigers have fur and four legs. These characteristics are common to all mammals, including these three animals.