Among the four normal distributions with probability density functions as shown below, which one has the lowest variance?

Probability distribution function for normal distribution is given by

$f\left(x\right)=\frac{1}{\sigma \surd \pi }{e}^{-}\frac{{\left(x-\mu \right)}^2}{2{\sigma }^2}$

Variance = σ²

For lowest variance, σ should be lowest

And if σ decreased, f (x) will increase

So, curve will have highest peak.