To solve this problem, we need to understand what the 'Ti plasmid' of Agrobacterium tumefaciens stands for.$\newline$Let's analyze the options:$\newline \bullet$Option 1: Tumor inducing plasmid$\newline$ - The 'Ti plasmid' is known for its role in causing crown gall disease in plants.$\newline$ - It transfers a segment of its DNA to the plant, leading to tumor formation.$\newline$ - Therefore, 'Ti' stands for 'Tumor inducing'.$\newline \bullet$Option 2: Temperature independent plasmid$\newline$ - This option is incorrect as the 'Ti plasmid' is not related to temperature independence.$\newline \bullet$Option 3: Tumour inhibiting plasmid$\newline$ - This option is incorrect because the 'Ti plasmid' induces tumors, rather than inhibiting them.$\newline \bullet$Option 4: Tumor independent plasmid$\newline$ - This option is incorrect as the 'Ti plasmid' is directly involved in tumor formation.$\newline$Based on the analysis, the correct answer is Option 1: Tumor inducing plasmid.