Genetic engineering involves identifying DNA with desirable genes, introduction of identified DNA into the host, maintenance of introduced DNA in host and transfer of DNA in it progeny.##@

The correct answer is option 'C': 3, 4, 1, 2. Here is an explanation of the steps involved in genetic engineering:

1. Identifying DNA with desirable genes: The first step in genetic engineering is to identify the DNA sequence that contains the desirable genes. This can be done through various techniques such as DNA sequencing, gene mapping, or screening of gene libraries. The desirable genes may code for specific traits or proteins that are of interest.

2. Introduction of identified DNA into the host: Once the desirable DNA sequence has been identified, it needs to be introduced into the host organism. This can be achieved through various methods such as transformation, transfection, or viral vectors. The aim is to deliver the DNA sequence into the host's cells so that it can be incorporated into the host's genome.

3. Maintenance of introduced DNA in the host: After the DNA has been introduced into the host, it needs to be maintained and replicated in the host's cells. This ensures that the desirable genes are continuously expressed and passed on to subsequent generations. The introduced DNA may be integrated into the host's genome or maintained as an extrachromosomal element, depending on the method used for introduction.

4. Transfer of DNA in its progeny: Once the introduced DNA has been maintained in the host, it needs to be transferred to the host's progeny. This can occur through normal reproductive processes such as sexual reproduction or asexual reproduction, depending on the organism. The transfer of the introduced DNA ensures that the desirable genes are inherited by the next generation.

In summary, the correct order of steps involved in genetic engineering is 3, 4, 1, 2. First, the desirable DNA sequence with the desired genes is identified. Then, the identified DNA is introduced into the host organism. Next, the introduced DNA is maintained and replicated in the host's cells. Finally, the DNA is transferred to the host's progeny to ensure inheritance of the desirable genes.