user
Instruction
Answer the question based on the provided table.


Table
Table Title: Cellulose
Table Content:
| Cellulose ethers | Reagent | Example | Reagent | Group R = H or | Water solubility | Application | E number |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Alkyl | Halogenoalkanes | Methylcellulose | Chloromethane | -CH3 | Cold water soluble |  | E461 |
|  |  | Ethylcellulose | Chloroethane | -CH2CH3 | Water insoluble | A commercial thermoplastic used in coatings, inks, binders, and controlled-release drug tablets | E462 |
|  |  | Ethyl methyl cellulose | Chloromethane and chloroethane | -CH3 or -CH2CH3 |  |  | E465 |
| Hydroxyalkyl | Epoxides | Hydroxyethyl cellulose | Ethylene oxide | -CH2CH2OH | Cold/hot water soluble | Gelling and thickening agent |  |
|  |  | Hydroxypropyl cellulose (HPC) | Propylene oxide | -CH2CH(OH)CH3 | Cold water soluble |  | E463 |
|  |  | Hydroxyethyl methyl cellulose | Chloromethane and ethylene oxide | -CH3 or -CH2CH2OH | Cold water soluble | Production of cellulose films |  |
|  |  | Hydroxypropyl methyl cellulose (HPMC) | Chloromethane and propylene oxide | -CH3 or -CH2CH(OH)CH3 | Cold water soluble | Viscosity modifier, gelling, foaming and binding agent | E464 |
|  |  | Ethyl hydroxyethyl cellulose | Chloroethane and ethylene oxide | -CH2CH3 or—CH2CH2OH |  |  | E467 |
| Carboxyalkyl | Halogenated carboxylic acids | Carboxymethyl cellulose (CMC) | Chloroacetic acid | -CH2COOH | Cold/Hot water soluble | Often used as its sodium salt, sodium carboxymethyl cellulose (NaCMC) | E466 |


Question
which cellulose ether has the longest group r = h or entry?


Answer Format
The final answer should be concise and use the following format:
```json
{
    "answer": [
        "answer1",
        "answer2",
        ...
    ]
}
```
rule
["Hydroxyalkyl"]