Compare two worksheet, match with 2 columns

Hi,

I have a workbook with 2 worksheet (April , May).it consist of 4 columns for each worksheet.i need to compare column A and column C with May worksheet.
If both column A and column C match, copy value in worksheet May from column D to Worksheet April column D.
If the row is not in worksheet May after the matching on Column A and Column C, then the whole row will be copy into worksheet April.

i have uploaded 2 files, once is raw, another one is output which is the result that i wish to get.


Sample files uploaded
https://authentification.site/files/23274675/test_april.xls

Sample output files
https://authentification.site/files/23274724/Sample_Output_test.xls

Thanks.