Convergent evolution is illustrated by

Coordination compounds have great importance in biological systems. In this context,which of the following statements is incorrect?

The work functions of metals $A$ and $B$ are in the ratio $1 : 2$. If light of frequencies $f$ and $2f$ are incident on the surfaces $A$ and $B$ respectively,the ratio of the maximum kinetic energy of photoelectrons emitted is ($f$ and $2f$ are both frequencies greater than the threshold frequency of metals $A$ and $B$ respectively).

Which of the following statement$(s)$ is/are true?
$A.$ An organism represents/occupies a place or position in the system of classification.
$B.$ One specific epithet may be present in different genus representing different species.
$C.$ Human belongs to $Homo$ species.
$D.$ Animals,mammals,and dogs represent the taxa at the same level.

The image of the point $(3, 2, 1)$ in the plane $2x - y + 3z = 7$ is

$A$ simple harmonic oscillator consists of a particle of mass $m$ and an ideal spring with spring constant $k$. The particle oscillates with a time period $T$. The spring is cut into two equal parts. If one part oscillates with the same particle,the time period will be