Equation of sphere whose centre is at $7\overline{\mathrm{i}}—4\overline{\mathrm{j}} + \overline{\mathrm{k}}$ and radius $\left|3\overline{\mathrm{i}}-2 \overline{\mathrm{j}} + 5\overline{\mathrm{k}} \right|,$ is

${{\overline{\mathrm{r}}}^{ }}^2 -2\overline{\mathrm{r}}.(3\overline{\mathrm{i}} - 2\overline{\mathrm{j}} + 5\overline{\mathrm{k}} ) + 28 = 0$

${{\overline{\mathrm{r}}}^{ }}^2 -2\overline{\mathrm{r}}.(3\overline{\mathrm{i}} - 2\overline{\mathrm{j}} + 5\overline{\mathrm{k}} ) - 28 = 0$

${{\overline{\mathrm{r}}}^{ }}^2 -2\overline{\mathrm{r}}.(7\overline{\mathrm{i}} - 4\overline{\mathrm{j}} + \overline{\mathrm{k}} ) - 28 = 0$

${{\overline{\mathrm{r}}}^{ }}^2 -2\overline{\mathrm{r}}.(7\overline{\mathrm{i}} - 4\overline{\mathrm{j}} + \overline{\mathrm{k}} ) + 28 = 0$