The correct answer is (d) 0.1×0.05
The best explanation: During discretization, when a mesh is made, care should be taken to avoid elements with very large aspect ratios (i.e. the ratio of one side of an element to the other). For a>b, if axb are dimension (mm) of rectangular element then it is given that a/b should not be more than 10. The smaller the element the finer is the mesh.